Process for the manufacture of halogenated alcohols



Patents 1,5'72,742 and 1,725,054.

Patented Oct. 17, 1933 PROCESS FOR THE HALOGENATED ALCOHOLS- MANUFACTURE "on Hans Meerwein, Marbixr'g, andErich GothfWupF pertal'-Elberfeld,, Germany, assignors to Winthrop Chemical' Company, Inc.,

N. Y a corporation of New' York; New-York i No Drawing. Application Nove mber$84, 1931,

Serial No. 577,15 29, 1930 The present invention relates to a processof preparing halogenated alcohols from halogenated aldehydes, said process being an improvement in or further development of the processes of U: S.

It is, a known fact in the art of reducing halogenated aldehydes to the. correspondingalcoholsz that the halogenated aldehydes occupy an excep tional position with regard to other aldehydes, inasmuch as the alcoholates. of magnesium which are known to reduce the non-halogenated aldehydes to the corresponding alcohols without difficulty, fail completely in the case of'the halogenated aldehydes: As we have established by experiments, likewise the alcoholates of all met- 'als of the'first-and second group'of the periodic system do not operate when trying to reducehalogenated aldeh'ydes by means of the said metalalcoholates. Up to date only aluminium alcohollates have proved as suitable metal alcoholates orsecondary alcohol., a I

for the reduction of the halogenatedlaldehydes" to the corresponding halogen alcohols -(compare U. S. Patents 1,572,742 and 1, 725,054). This reaction is carried out inthe: presence ofa primary In accordance with the present invention the; reduction of halogenated aldehydes to the corre sponding halogenated alcohols is effected by treating the halogenated aldehydes in the prese ence of a non-tertiary alcohol withan alcoholate:

of a metal other than aluminium and the metals; of the first and second group of the periodic system. Owing to the fact that up to date only aluminium alcoholates could be used for the re- ;duction of halogenated aldehydes, but not, for

example, magnesium alcoholate which is capa ble of transforming only non-halogenated aldehydes into the corresponding alcohols, it is sur aluminium and those of the firstjand second group of the periodic system may be employed in the process of preparing halogenated alcohols" from the'corresponding aldehydes. Apparently the metal alcoholates effect the reduction process bya catalytic action since, ingenera1, it-;lsnot necessary to introduce equivalent quantities-"ofthe metal alcoholates into the reaction; 1 The? process proceeds according to the following reaction scheme: I 1

RCHO+.Hz-, RCHQH (R being a halogenated organic, for example; a halogen alkyl, halogen aryl or halogenated arylalv kyl radical).

The hydrogen involved in this reaction is sup- 9, and in Germany November .35 Claims. (cited-1 56)? plied by the non-tertiary. alcohol present solvent'or also by the alcoholradical present the 'metal alcoholate, the= alcohols transforming for .their part into the corresponding aldehydes.

When performing our new processawepreferc to use'the metalalcoholates of the metals of the 5 fourth group'of the; periodic system and pf the iron :group, especially the alc'oholates of zirconium, titanium, tin and iron. Other metals which; are, however, not of such great practical interest are, for instance, boron, v thallium, lead,-;rnanganese, cobalt and nickel. The metal-alcoholates,-; are obtainable by, reacting upon themetalhalogenides with: the alkali metal alcoholateajor, example, according to the following equation;

.mec1,.+nNaoc,H :m oo,H1 .+.nNac1 me indicatinga metal, 11; indicating the'valency of the metal, As equivalents'halogen metal al-,

(n ,having the above meanings being a number.

, smaller than; 11), may bejem'ployed instead of the l pure metal 'alcoholates. Such halogen metal alcoholates,-obviously, may also beproducedby-reacting with hydrohalic acids upon the metal alcoholates. As already-indicated above, in general, smaller-quantities of ,themetal alcoholates than those. which correspond to equivalent;

amounts, may. be employed; For instance, in

some cases already, the sixth part lent quantity proves operable.

-ofthe equivaasisopropyl alcohol, isobutyl alcohol. and ,cyclo-v, hexanol, but; also primary ,alcohols,-..espeoially.

As non-tertiary alcohols beingQpres'ent as :solventiweuse preferably secondary alcohols,- such prising that also alcoholates of metals Otherthafri ethyl-. and propylealcohol, further, for example, benzyl alcohol have proved operable. When us ing a suificient quantity of the'metalalcoholate;

it is notnece'ssary that larger quantities of a'free non-tertiary-alcohol' are present in the reduction f mixture. The-metal..alcoho1ates and thenonteritiary alcoholsma'y; each be employed also-in admixture-with one another. 1 t

The non-.tertiaryalcohol to be used as -.a-sol 7 vent, or reducing agent, 1111111118 reaction mixture is advantageouslychosendependent. on the boiling points .of the h'alogenated aldehyde :to be.

reduced and of thevhalogengalcohol formed since' ithas provediadvis'ableto distil voft "during; the l 1105 reactionthe aldehyde or the ketone formed from ducing agent, and is preferably between 70 and ing point. Accordingly the reaction temperature is dependent on the boiling point of the nontertiary alcohol being present as solvent or re- 120 C. When using a relatively small quantity of the non-tertiaryalcohol the temperature maybe relatively high in comparison with the boiling point of the non-tertiary alcohol, sinc'e,jof course,

the mixture in such case has a higher boilingfor example, tribromoand trichloroacetaldehyde,

..=furthermore;' alpha-,f alpha, beta-trichloro butyraldehyde, alpha- 'chlor0-' and alphabromo-crotonaldehyde. Suitable halogenated aromatic aldehydes are, for example, halogenbenzaldehydes, halogen cinnamic aldehyde and the-like. s r

'Our new process is advantageously performed in the-following manner: .the solution of the metal alcoholate in the non-tertiary alcohol as obtained'by the action of an alkali alcoholate Jfsolution upon the metal halogenide is 'mixed with the halogenated aldehyde and, while heating and .passing through an indifferent gas, the solvent} is distilled off; always'the quantities of the non-tertiary alcohol distilled oil are replaced .by the non-tertiary'alcohol. With the solvent distilling off simultaneously the dehydrogenated alcohol, being an aldehyde or ketone, is removedfrom the reaction mixture as quantitatively as possible; then the mixture is acidified and the ihalogen aldehyde, produced in general in a good yield, may be separated bysteam distillation or by extraction with an organic solvent.

The'invention is illustrated by the following examples without being restricted thereto: Example 1 7 13.1 grams of zirconium tetrachloride are dissolved in 76.2 gramsof absolute isopropyl alcohol. This solution is dropped slowly into a boiling sodium isopropylate solution (from 4.76 grams of sodium and 76.2 grams of absolute isopropyl alcohol) ,whereupon sodium chloride is precipitated in a finely divided form. .Thejmilky liquid is maintained at the boiling pointfor some time longer under a reflux condenser, 140.5 grams of bromalare added and the solvent which must be continually replaced is distilled off while passing through nitrogen. Almost the theoretical quantity of acetone passes over with the solvent After some-5V2 hours the greater part of the solvent remaining is distilled off, dilute sulfuric acid is addedand'the tribromoethyl alcohol, which is produced in a very good-yield, is driven'ofi' by -means' of steam and isolated by known methods.

The treatment of the sodium'isopropylate solution with the zirconium tetrachloride solution can likewise be carried out at room temperature.

Instead of the zirconium tetra-isopropylate used above' thereactio'n may be performed with 1a..halogen-zirconium isopropylate, for instance,

the non-tertiary alcohol having the lowest boilwith mono-chloro-zirconium-tri isopropylate, being produced by using for the preparation of the sodium isopropylate tobe added to the zirconium tetrachloride only 3.57 grams'ofsOdium metal or'by adding about 40 grams of a 5% solution ofhydrochloric acidin isopropyl alcohol.

7 Example 2 V 14.5 grams of stannic tetrachloride are dropped into a sodium isopropylate solution (from 5 grams of sodium andj160 grams of absolute isopropyl'alcohol). 77 grams of chloral are then added gradually to the boiling solution. The distillation of the solvent, which must be continually replaced, is then begunin a current of an indifferent gas. After some 6 hours the greater lute sulfuric acid is then added and the trichlorethyl alcohol, which is produced in a very satisfactory yield, is driven off by means'of steam and isolated.

Instead of stannic chloride there can also be'.

added to the sodium isopropylate the equivalent quantity of another appropriate metallicsalafor example, titanium tetrachloride, in order to carry out the reduction by means of titanium isopropylate; or, instead of the above indicated,

quantity of zirconium tetrachloride a mixture of, for instance, 6.6 grams of zirconium chloride and 7.3 grams 'of stannic chloride may be used;

Example 3 p 'part of the solvent remaining is distilled off. Di-

9.1 grams of anhydrous ferric chloride aredissolved in 90 gramsof absolute isopropyl alcohol. This solution is run. into a boiling sodium isopropylate solution (from 3.7 grams of sodium and 70 grams of absolute isopropylalcohol). After the addition of 140.5 grams of brornal'the distil- 'lation of the solvent is begun.- .After some 6.

hours tribromoethyl alcohol is formed in a'very satisfactory yield and is isolated as described in ExampleL- v I Example 4 37.3 grams of tin ethylate are heatedto about 80 C. for about 3 hours with 25 grams of absolute ethyl alcohol and 140.5 grams of bromal,-

advantageously while passing through an indifferent gas.- When nearly the theoretical quan-' tity of acetaldehyde has'been evolved, dilute sulfuric acidis added'and the tribromoethyl alcohol is separated in-the' manner already described.

Example 5 .From'1-3 grams of zirconium tetrachloride in i 76 grams ofabsolute isopropanol and 4.7 grams ofsodium in-76 grams of isopropanol a solution of zirconium isopropylate in ,isopropanolis prepared in accordance with the directions given in 7 Example 1. .52 grams of alpha-chloro-crotonal-- dehyde aredropped into this solution and during 3. hours a mixture of isopropanol and acetoneis distilled off while 7 passing through nitrogen and. continually replacing the solvent which distils off... The residue is then treated with dilute sulfuric acid and the alpha-chloro-crotylalcohol,

isolated,

whichiis produced in a very good yield is by known methods. 7

'By using instead of the alpha-chloro-cinnarnic aldehyde and working up in the same manner, alpha-chloro-cinnamic alcoholis obtained. V v

Example 6 v A solution of 16 grams of zirconium tetrachlo- I ride inlOO' grams of water-free propyl alcohol above indicated quantity of alpha-chloro-crotonaldehyde 84 grams of isgm ixeiiwitha solutionofa 6.75 grams of sodiuxmin-IOQ grams of propyl alcohol while hot. After the addition of 140.5 grams of-tribromoaceta ldehyde, themixture is heated at 95 C. li during tlhours, Then the propionic aldehyde formed and .the main part of the solvent are distilled oif. dilute sulfuric acid i s added and the.

' ed gfromthe group consisting of metal-alcoholates halogen-metal alcoholates of monohydric,

nomtertiary alcohols, with a metal other than aguminium and the metals'of the'first and second-group ofthe periodic system in the presence of a non-tertiary alcohol. V

2. The process which comprises reacting. upon ahalogenalkyl aldehyde with an alcoholate select-j ed irom the group consisting of metal-alcoholates halegemmetal-alcoholates of monohydric 'non tertiary alcohols with a metal} other than aluminium and the metals of the first and secopd group of the periodic system in the presence of anon-tertiary alcohol.

39- 3.;;The process which comprises reacting upon a. halogenated acetaldehyde with an alcoholate selected from the group consisting of metal-alcoholates and halogen-metal-alcoholates of monohgdric-non-tertiary alcohols with a metal other -than aluminium and the metals of the first and second groupof the periodic system in the presence of a non-tertiary alcohol. I

4. The -process which comprises reacting upon tribromoacetaldehyde with an alcoholate selected from the group consisting of metal-alcoholates and halogen-metal-a1coholates of monohydric non-tertiary alcohols with a metal other than aluminium and the metals of the first and second group of the periodic system in the presence '45., of a non-tertiary alcohol.

' 5. The process which comprises reacting upon a halogenated aldehyde with an alcoholate selected from the group consisting of metal-alcoholates and halogen-metal-alcoholates of monohydric Warren-tertiary alcohols with a metal of the fourth group of the periodic system, in the presence of a non-tertiary alcohol.

6. The process which comprises reacting upon a halogenalkyl aldehyde with an alcoholate selectal ed from the group consisting of metal-alcoholates and halogen-metal-alcoholates of monohydric non-tertiary alcohols with a metal of the fourth group of the periodic system, in the presence of a non-tertiary alcohol.

0': 7. The process which comprises reacting upon a halogenated acetaldehyde with an alcoholate 9. The process which comprises reacting upon ea halogenated aldehyde with an alcoholate selectmonohydricnon-tertiary alcoholtin the presence of a non-tertiary alcohol. 1 a

- i 10.-The process which comprisesireacting upon a halogenalkyl aldehyde with an. alcoholate. selected from the group consisting otzirconiumalcoholates and halogen-.zirconiumalcoholates of a monohydric non-tertiaryalcohol in the presence.

of a non-tertiary alcohol.

11;. The process whichxcomprisesreacting upon a halogenated. acetaldehyde withlan alcoholate selected from the group consisting of zirconiumalcoholates and halogen-zirconium-alcoholates o1 afmonohydric non-tertiary alcoholin the presence of a non-tertiary alcohol while heating. 7 .12. 'The' process which comprises reacting upon I tribromoacetaldehyde with an alcoholateselected from the group consisting of zirconium-8,100+ holatesand halogen-zirconium-alcoholates of a- 15. The process which comprises reacting upon a .halogenalkylaldehyde with an alcoholate selected from the group consisting of.zirconium-':

.alcoholatesfand halogen-zirconium-alcoholates-of a monohydric non-tertiary alcohol in the presence of a secondary alcohol. 1 I

. 16. The process which comprises reacting upon a halogenated aldehyde with an alcoholate selected from the group consisting of zirconium-alcoholates and halogen-zirconium-alcoholates of a monohydric non tertiary alcohol in the presence of isopropyl alcohol. 3 a

1'7. The process which comprises reacting upon a halogenalkyl aldehyde with an alcoholate selected from the group consisting of zirconium-alcoholates and halogen-zirc'onium-a1coholates of a monohydric non-tertiary alcohol in the presence. of isopropyl alcohol. e

18. The process which comprises reacting upon a halogenated acetaldehyde with an alcoholate selected from the group consisting of zirconiumalcoholates and halogen-zirconium alcoholates of I a monohydric non-tertiary. alcohol in the presence of isopropyl alcohol while heating.

19. The process which comprises reacting upon trioromoacetaldehyde with an alcoholate selected from the group consisting of zirconium-alcoholates and halogen-zirconium-alcoholates of a monohydric non-tertiary alcohol in the presence of isopropyl alcohol while heating. 1, 20. The process which comprises reacting upon trichloroacetaldehyde with an alcoholate selected from the group consisting of zirconium-alcoholates and halogen-zirconium-alcoholates of 'a monohydric non-tertiary alcohol in the presence of isopropyl alcohol while heating.

21. The process which comprises reacting up on a halogenated aldehyde with the isopropylate of zirconium in the presence of isopropyl alcohol.

22. The process which comprises reacting upon 5 zirconium in'the presence of isopropyl alcohol.

23; The process which comprises reacting upon a halogenated acetaldehyde with the isopropylate of zirconium in the presence of isopropyl alcohol while heating. c

a '24. The process which comprises reacting upon tribromoacetaldehyde with the isopropylate of zirconiumwin the presence of isopropyl alcohol while heating.

. 25;. Theprocess which comprises reacting upon .trichloroacetaldehyde with the isopropylate of' zirconium-in theipresence of isopropyl alcohol while heating.

26-. The process whichcomprises reacting upon a halogenated aldehyde with an alcoholate se-' lected from-the group consisting of metal-alcoholates and halogen-metal-alcoholates of a monohydric non-tertiary alcohol with a metal .of the iron group. in the presence'of a non-tertiary a1- cohol. l

27. The process which comprises reacting upon a halogen alkylaldeh-yde with an .alcoholate'selectedgfrom the group consisting of metal-alco-v holatesand halogen-metal alcoholates of a monogroup in the present of anon-tertiary alcohol while heating. a

- 29; The process which comprises reacting upon 7 ahalogenated aldehyde with an alcoholate selected from the group consisting of iron-alcoholates ary alcohol while heating.

v 1,931',2o4 a halogenalkyl aldehyde with the isopropylateof and halog'ii-iion-alcoholates' of a, monohydric" non-tertiary alcohol in the presence of' a non: tertiary alC hol. I I 11 30. The process which comprises reactingupo'n a halogenalkyl aldehyde with an alcoholatese lected from the group consisting of iron-alcohol; ates and halogen-iron-alcoholates' of a monohydric non-tertiary alcohol in the presence of a non-tertiary alcohol. 31'. The process which comprises reacting upon tribromoacetaldehyde with an alcoholate selected fromthe group consisting of iron-alcoholatesjar' 'd. halogen-iron-alcoholates of a 'monohydric nontertiary alcohol in the presence of anon-tertiary alcohol while heating. 1

32. The process which comprises reacting upon a halogenated aldehyde with an alcoholate select edfrom the group consisting of iron-alcoholates and halogeniron-alcoholates of a monohydrie non-tertiary alcohol in the presence of a second- The process whichcoinprises reacting'u po a halogenalkyl aldehyde-with an alcoholateseI- lected from the group consisting of iron-alcohol ates and halogen-iron alcoholates of a monohydric non-tertiaryalcohol in the presence of a sec ondary alcohol while heating. 1 7

34. The process which comprises reacting upon tribromoacetaldehyde with an alcoholate'selected from the group consisting of iron-alcoholatesiand halogen-iron-alcoholates of 'a vmonohydric nontertiary alcohol in the presence of isopropyl alco-'- 1101 while heating. r

35. The process which comprises reacting upon tribromoacetaldehyde with iron isopropylate'in' the presence of isopropyl alcohol while heating.

' j HANS MEERWEIN.

ERICH GOTH. 

